Totally-inclosed electric machine



July 31, 1928. 1,678,883

L. STEIN ER El AL TOTALLY INCLOSED ELECTRIC MACHINE Filed Jan. 22, 1926 Patented July 31, 1928.

UNITED STATES PATENT. orrlca.

ITUTDWIG OF BERLIN, AND 'VIGIOB GUTMANN, OF NUBEHZB-EBG, GER-Em,

ASBIGNOBS, BY KESNE ASBIGNIENTS, TO WESTINGHOUSE ELECTRIC & IANUIAG-' TUBING GOIPANY, A CORPORATION OF PENNSYLVANIA.

'ro'rmY-mcmsnn nnncrnrc mom.

Application fled J 28, 1928, Serial No. 83,144, and in Germany April 27, 1925.

Our invention relatesto a totally inclosed electric machine and more particularly to a shaft sinking or mine pump motor.

Our. invention consists of a further improvementof the electric machine described and claimed in a prior application Serial No.

67,653, filed Nov. 7, 1925, by Hans Richter and assigned to the Westinghouse. Electric & Manufacturing Company. The stufling box of the shaft and the casing or shell of this rior machine stand normally under liqui pressure. In the prior invention, the

sealing of the machine casing is effected in such a manner that small quantifies of 1 liquid are'allowed to penetrate into the easing, but a sump or collecting vessel is provided at the lower end of the machine casing for catching the liquid which has penetrated and in this sum or collecting vessel a pum is located WlllCh ejects the liquid again cm the casing.

It is not desirable to drive this sump pump permanently by the electric motor, as in said prior invention, because it would eject air 2 from the casing after all the liquid has been removed and would thus increase-the difi'erence of pressure at the stufiing box which is, of course, undesirable. For this reason, we have provided a coupling or clutch between the pump. and the electric motor, which is thrown into gear only when a certain quantity of liquid has collected in the collecting vessel or sump.

The construction or design'of the coupling ofiers special difliculties in the present case.

Th machine forming the object of our invention is intended specially for borings in shaft sinking operations. It is of elongated and slender design and there is little room 40 for housing the coupling within its casing.

' Since the machine is ex ected to work under unfavorable service con itions sometimes for several weeks in a bore hole of great depth without any attendance whatever, it is necessary that the coupling should be of simple construction and capable of withstanding rough usage. Couplings with a device for throwing it in gear operated by a float, as proposed for other conditions of machines,

are for this reason quite unsuitable in the boring of shafts.

According to our invention, the problem is solved by connecting the motor with the" sump pump by a liquid friction coupling.

- Such couplings are known but have never before been employed for this purpose. According to our invention, the coupling is located in the sump in such manner that the liquid rises into it and couples the pump with the motor when the level of the liquid in the sump has attained a certain height and the liquid retires from the coupling and releases the pump from the motor when the level of the liquid has dropped below a critical level owing to the discharge of the liquid from the casing.

An embodiment of our invention is illustrated in the drawing aflixed hereto, wherein Fig. 1 is a view in longitudinal section of the complete mine or well pumping motor, the main pump, which is normally located above the motor, having been omitted as forming no part of our present invention.

Fig. 2 is a detail view of the liquid friction coupling in partial vertical section on a larger scale, and

Fig. 3 is a fractional detail view of the coupling in horizontal section on a still larger scale.

' Referring to Fig. 1, the motor M is provided in a casing having a sump or collecting vessel S in its lower part, wherein is located-a sump ump P which is connected to the motor sha by a liquid friction coupling K. The sump pump draws the liquid in through the bore 1 and discharges it from the casing at 4 by the pipe 2 in which av non-return valve-is provided at 3. We prefer toutilize a sump pump with rolling pistons although, of course, any other suitable type may be employed. v

The liquid friction coupling K has the following construction. Referring in par,- ticular to Fig. 2, it will-be seen that upon the lower end 5 of the motor shaft is firmly mounted or keyed a collar 6 having a pcripheral shell or cylindrical .flange 7. The outer circumference of the shell 7 is pro: vided with teeth 8, in the manner of a circular saw, and with a plurality of radial bores 9.

Upon the upper end of the sump pump is integral with a cylindrical shell or flange 12 surrounding the shell 7 with a small clearance, and provided with teeth 13 upon its inner circumference, as indicated more clearly in Fig. 3.

The outer circumference of the shell 12 is provided with a closely fitting angular 12 and in the angular ring 14 and are held by, or are integral with, a semi-circular spring ring 17 located in a milled groove in a portion of-the shell 12 which projects downwards over the outer circumference of the disc 11. The hub of the disc 11 is provided with a plurality of oblique bores 18. In the shell 12 and the angular ring 14 fine bores '19 are provided at diametrically opposite points of the circumference closely above, or in alignment with, the upper face of the disc 11. y

The manner of operation of the device is as follows: As soon as the motor is immersed in the liquid within the bore hole the hydrostatic pressure of the column of liquid above it acts upon the packin 's surrounding the shaft of the motor M. nder the action of this pressure, liquid leaks slowly into the casing of the machine. In the absence of suitable provisions, the leaking would cease only whegi the air in the machine casing had ins through the bores 18 and the clearancebelow the shell 7, and partly through the bores 19.

When the liquid has reached a certain level AA, Fig. 1, in this space, the disc 11 is carried along by the shell 7. As soon as the disc 11 has attained a certain speed a large quantity of liquid is conveyed into the annular space between the two concentric shells or flanges 7 and 12 through the bores 9, owing. to the centrifugal action of the liqu'd, and the'space becomes completely filled up with liquid within the range of the teeth 8 and 13.

Although a certain slip occurs between.

amply suifices to the shaft 10 of the sumppump again be;

- comes inoperative.

Various modifications and chan es may be made without departing from the spirit and the scope of the invention, and we desire, therefore, that only such limitations shall be placed thereon as are imposed by the following claims when read in the light of the prior art.

We claim as our invention:

1. A-totally inclosed electric motor for operating immersed in a liquid, with a sump been so strongly compressed that its pres within the casing for the liquid which has dinarily inoperative.

sure balanced the hydrostatic pressure of the liquid. This does not happen, however, because as soon as a certain quantity of liquid has collected in, the sump, it is ejected again uicker rate than that at which itat a far has leake into the casing. In this manner the initial state is restored again. The use of a coupling capable of disengagement prevents the pump from ejecting air also. from the casing, which would increase the pressure difference acting at the packings, as above pointed out.

The liquid coupling operates in the fol lowing manner. The motor shaft 5, with the disc 6, is rotated continuously, as is also the main pump (not shown) which is located above the motor. The shaft 10 of the sump or auxiliary pump, with the disc 11, is or- If now the sump of the motor becomes filled with liquid, the level of the rising liquid first reaches the disc 11 at the outer mouths of the bores 18. When the liquid continues to rise, the bores 18 gradually becomes filled with liquid and finally the liquid enters the annular space between the shell 7 and the shell l2, partly leaked into the casing, a pump for draining said sump, and a liquid friction couplin for detachably connecting the motor sha with the shaft of said pump.

2. A totally inclosed electric motor for operating immersed in a liquid, with a sump within the casing. for the liquid which has leaked into the casing, a pump for draining said sum and a. liquid friction coupling .for detac ably connecting the motor shaft with the shaft of said pump, said coupling being located in the sump in such a position that the liquid penetrates into it and couples the pump with the motor when the. level of liquid in the sump has attained a certain height and drains out of said coupling and 4;. An inclosed submersible .motor having a sump in the bottom thereof, and a liquidlevel-responsive pump mechanism in the sump for expelling the fluid contents of the sump only when a liquid has reached a predetermined range of levels therein.

5. An inclosed submersible motor having a sump in the bot-tom thereof, and pumping mechanism operative only on a liquid content and not on a gaseous content in the sump for expelling the liquid therefrom when it has reached a predetermined range of levels therein.

6. An inclosed submersible motor having a sump in the bottom thereof, a sump pump for draining the sump of accumulations of liquid, and a coupling mechanism operative only on a liquid content and not on a gaseous content in the sump for coupling the sump pump to the motor shaft.

7. An inclosed submersible motor having a sump in the bottom thereof, a sump pump for draining the sump of accumulations of liquid, and a liquid-friction clutch device which engages the drainage pump to the mo tor shaft and drives it until the liquid suction breaks in the clutch device.

8.An inclosed submersible motor having a sump in the bottom thereof, a sump pump for draining the sum of accumulations of liquid, and a liqui -level-respon sive coupling for driving and disconnecting the sump pump from the motor shaft, said coupling being a liquid-friction clutch comprising a cup-shaped clutch member attached to one shaftand a male clutch member on another shaft, said clutch members having internally and externally directed teeth in closely spaced relation, whereby one clutch member is driven from the other only when a liquid is interposed therebetween.

9. An inclosed submersible motor having a sump in the bottom thereof, a sump pump for draining the sump of accumulations of liquid, and a liquid-level-responsive coupling for driving and disconnecting the sump pump from the motor shaft, said coupling being a device for transmitting torque in response to a liquid pressure developed in the cgupling for driving said sump motor, the torque developed by gas pressure when the coupling is immersed in a gaseous medium being insufiicient to drive said sump motor.

'In testimony whereof we affix our signatures.

' 'LUDWIG STEINER.

VICTOR GUTMANN. 

